This invention relates to irrigation sprinkler nozzles, and more particularly to a new and improved sprinkler nozzle construction for producing a highly controllable and enhanced spray pattern from a nozzle of the type including a primary or range nozzle and a secondary or spreader nozzle.
In many irrigation applications, particularly in commercial irrigation situations, irrigation sprinklers will employ nozzles having two or more outlets. Typically, one nozzle outlet, referred to as a "range nozzle", is designed to produce a relatively large volume stream intended to be projected outwardly from the sprinkler for maximum distance of throw, and another nozzle outlet referred to as a "spreader nozzle", is designed to produce a smaller volume stream, typically as a relatively small droplet size spray, which is intended to fall-out close in to the sprinkler for close-in watering. In some cases, a third nozzle outlet is provided to produce an intermediate range stream, the object being to insure that water is distributed over the entire area between the sprinkler and the maximum range of the water projected outwardly therefrom.
While it is relatively straight forward to design a range nozzle to achieve maximum distance of throw, it is much more difficult to design a spreader nozzle to fill in the area between the sprinkler and the doughnut shaped area of coverage produced by the range nozzle. One reason why it is more difficult to design spreader nozzles to supply close-in water is that small sized orifices and passageways have typically been required so that a relatively small droplet size spray will be produced, the finer the spray, the more rapidly the water will fall out to the ground. Small size orifices and passageways, however, suffer from being easily clogged and restricted by particulate material such as sand and dirt carried by the water, thereby rendering the nozzle ineffective. Further, such fine, sometimes mist-like sprays are difficult to control and highly susceptible to being blown by wind so that the water distribution pattern produced may be quite irregular. Moreover, the typical spray produced by prior art spreader nozzles tends to be generally conical in shape so that the spray extends laterally to the side of the range nozzle stream, thereby producing significant lateral overspray when used with part circle sprinklers.
Thus, there exists a need for a new and improved nozzle construction which will provide an effective and reliable spreader nozzle for close-in watering, yet which does not require small size orifices and passageways, and will produce a spray pattern of controlled size and shape that is substantially unaffected by wind and does not produce objectionable lateral overspray. As will become more apparent hereafter, the nozzle construction of the present invention satisfies this need in a novel and unobvious manner.